Significant effects of Ganoderma lucidum polysaccharide on lipid metabolism in diabetes may be associated with the activation of the FAM3C-HSF1-CAM signaling pathway

Diabetes is a threat to patient health worldwide. Type 2 diabetes (T2DM), one of the two main types of diabetes, is a long-term metabolic disease caused by heredity and environmental factors. It has been reported that Ganoderma lucidum polysaccharide (GLP) significantly decreased the concentration of blood glucose, promoted insulin secretion, improved glucose tolerance and regulated the concentration of blood lipids. In the present study, a T2DM model was established in db/db mice, following which T2DM mice were treated with GLP (100 and 400 mg/kg) for 8 weeks, with MET used as the positive control. The glycosylated hemoglobin (HbAlc) and fasting blood glucose (FBG) levels, and diabetes-associated clinical chemistry indexes were detected in the blood and serum of each mouse. Hematoxylin and eosin, and oil red O staining were performed on the livers of each mouse to evaluate the level of liver fat. The expression levels of family with sequence similarity 3 (FAM3C), heat shock factor 1 (HSF1), calmodulin (CaM), AKT and phosphorylated (p)-AKT were detected in the hepatocytes of T2DM mice using reverse transcription-quantitative PCR and western blotting. The results demonstrated that the unbalanced levels of HbAlc, FBG and diabetes-related index in T2DM mice were significantly improved by treatment with GLP. Lipid droplets in the hepatocytes of mice shrank in the GLP groups compared with the model control group. The expression levels of FAM3C, HSF1, CaM and p-AKT/AKT in the hepatocytes of T2DM mice were significantly increased following treatment with GLP. In conclusion, GLP exerted significant effects on lipid metabolism in diabetes, which may be associated with the activation of the FAM3C-HSF1-CaM signaling pathway.

Insulinotropic and antidiabetic effects of β-caryophyllene with l-arginine in type 2 diabetic rats

Beta-caryophyllene (BCP) is a flavoring agent, whereas l-arginine (LA) is used as a food supplement. They possess insulinotropic and β cell regeneration activities, respectively. We assessed the antidiabetic potential of BCP, LA, and its combination in RIN-5F cell lines and diabetic rats. Ex vivo studies were carried out for glucose uptake and absorption of the combination of BCP with LA. The results indicated that the combination of BCP with LA showed a significant decrease in glucose absorption and an increase in its uptake in tissues and also an increase in insulin secretion in RIN-5F cells. The combination treatment of BCP with LA showed a significant reduction in glucose, lipid levels, and oxidative stress in pancreatic tissue when compared with the diabetic group. Furthermore, the combination of BCP with LA normalized glucose tolerance and pancreatic cell damage in diabetic rats. In conclusion, the combinational treatment showed significant potentials in the treatment of type 2 diabetes mellitus. PRACTICAL APPLICATIONS: Type 2 diabetes mellitus is the most prevalent chronic metabolic disorder affecting a large population. Beta-caryophyllene is a CB₂ receptor agonist shown to have insulinotropic activity. l-Arginine is a food supplement that possesses beta-cell regeneration property. The combination of BCP with LA could work as a potential therapeutic intervention, considering the individual pharmacological activities of each. We evaluated the antidiabetic activity of the combination of BCP with LA in diabetic rats using ex vivo and in vitro experimentations. Results from the study revealed that the combination of BCP with LA showed a significant (p < .001) reduction in glucose and lipid levels as compared to individual treatment. In vitro study also supports the diabetic potential of the combination of BCP with LA in the glucose-induced insulin secretion in RIN-5F cell lines. The study indicates a therapeutic approach to treat T2DM by BCP and LA combination as food and dietary supplement.